Nicolaus Copernicus (1473 - 1543)
Nicolaus was born in Poland, and was only 10 years old when his father (a merchant and local official) passed away. His uncle, a priest, ensured that Nicolaus had a good education, and in 1496 he travelled to Italy to study law. Whilst in Italy, he stayed with a professor of mathematics, who encouraged Nicolaus' interests in geography and astronomy.
After graduating from university, Nicolaus worked for the church for many years, following in his uncle's footsteps. During this time, he dedicated much of his life to astronomy. In the church, he spoke Latin, but Nicolaus was also fluent in Polish, German, Greek, and Italian.
In 1514, the Catholic church was seeking to improve the calendar. The Pope approached Nicolaus for help, as he was not only an established member of the church, but also a well-known astronomer. Nicolaus began to think about the motion of the Solar System, about the definition of a day and year, and about his observations of planets in the night sky. He developed a theory of a heliocentric Solar System, in which the planets orbit the Sun at the centre.
He published his ideas in his book De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), just before his death in 1543. The book suggested that the Earth rotates daily on its axis, and revolves yearly around the Sun. At the time, the church believed in the geocentric model, in which the planets, Sun, and stars all orbit the central Earth. However, Nicolaus' book did not cause much controversy in the church, until 73 years later when Galileo resurfaced its ideas.